Question

某汽车以xkm/h的速度行驶akm路程,若速度提高2km/h,则同样的路程可节约多长时间?

Answer 1

T=A/(X+2)-A/X

(X+2)XT=AX-A(X+2)

(X+2)XT=AX-AX-2A

(X+2)XT=-2A

T=-2A/(X+2)X